Canon Digital REBEL 300D Operator's manual

How To Remove the Canon Digital Rebel (300D) Focusing Screen
July 6, 2004
This guide provides instructions on how to remove the focusing screen for the purpose of either cleaning or to install a
new screen.
DISCLAIMER: THE INSTRUCTION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
ANY
KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. THE ENTIRE RISK AS TO THE EXECUTION OF THE BELOW INSTRUCTION
IS WITH YOU. SHOULD THE INSTRUCTIONS DAMAGE THE CAMERA, YOU ASSUME THE
ENTIRE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
1. Ensure that the camera is relatively dust free and that your work environment is dust free.
2. Remove the lens from the camera.
3. Place the camera on a towel upside down or on something so at least the camera is stable and relatively flat.
4. Looking within the camera, note the small metal tab behind the foam where the mirror hits when it lifts up as
shown below.
Focus screen
Metal bracket
Tab
Mirror
Shutter
Foam padding
5. Using a small tweezer, grip the little metal tab with the tweezer and push the tab gently towards the back of the
camera (1) then lift up (2) as shown below. The metal bracket should pop up. This does not take a lot of force to
accomplish. When lifting the metal bracket, ensure that it is firmly held and pulled away from the mirror to prevent
scratches on the mirror.
1
2
6. Using the tweezers again, use it to lift out the focusing screen by grabbing onto either tabs on the side of the
focusing screen. Lift it out slowly in the same manner how you did with the metal bracket (albeit lifting it an angle
will be slight more difficult as the small tab is being held by the tweezer). Note how the focusing screen is pulled
out as you'll want to ensure you put it back in the same way (and not upside down or reversed).

7. You'll notice a metal shim on the bottom, leave it there. You should have the parts as shown below (note the
metal shim was removed for illustration purposes only). Note that when you place the focusing screen on the
table, the back should be slightly lifted up due to the protruding extensions on the bottom.
8. Using an air blower, blow off any dust on both sides of the screen. Handle the focusing screen with one finger on
each side gripping the sides only to prevent oil from getting on the screen itself.
9. Before reinserting the focusing screen ensure that the metal shim that was left inside the camera is flushed to the
back, otherwise the shim will obstruct the viewfinder.
10. Insert the focusing screen back into the camera with the tweezers first angling it into place with the tab on the
back end of the screen inserted into the slot then drop into place. Ensure that the focusing screen is fitted
correctly and not at an angle.
11. Install the metal bracket in the same manner, at an angle where the two metal tabs on the back fits into the
appropriate slots then drop. To firmly put the metal bracket in place, push the tab towards the back using the
tweezer then down. The tab should “click” into place. Ensure that the metal bracket is aligned correctly.
12. Place the lens back on the camera and turn on the camera. Check that all focusing points are lit correctly by
selecting the 7-point focus. If any of the red dots are misaligned, most likely the focusing screen has been placed
in reverse. If you see a portion of the bottom screen blocked this indicates that the metal shim has shifted and
needs to be aligned against the back of the camera.
Metal bracket
Focusing screen
Metal shim